(80) 



37. Red-finned Shiner. Luxilus cornutus, Mit. (2.) Chiefly veg- 

 etable. Fragments of unrecognizable insects, a mass of confervoid algae 

 and parts of a netted-veined leaf. 



38. Silver Fin. Luxilus analostanus, Gir. (3.) Insects of several 

 orders and a few algae. 



39. Red Fin. Lythrurus diplaemius, Raf. (1.) A few small dip- 

 tera. 



40. Emerald Minnow. Notropis atherinoides, Raf. (2.) Several 

 small gnats, an unknown hemipter and a little vegetable matter. 



41. Silver-mouthed Dace. Ericymba buccata, Cope. (1.) A few 

 small larvae of diptera, much sand and indeterminable matter, partly 

 vegetable. 



42. Common Chuh. Semotilus corporalis, Mit. (1.) Many Ephemera 

 larvae and a larva apparently belonging to the Dytiscidae. 



SUCKERS. CATOSTOMIDAE. (24.) 



My observations on this family indicate that its food is chiefly animal, 

 consisting principally of mollusks, insect larvae and entomostraca. It is 

 not impossible that in this, as in some other cases, the proportion of veg- 

 etable food is under-estimated, owing to the rapidity with which it is di- 

 gested, as compared with the chitinous and calcareous coverings of arthro- 

 pods and mollusks. The intestines of the family contain usually large 

 quantities of mud. 



There seems to be a well defined difi"erence between the food of the 

 Catostominae (Red Horse) and that of the Bubalichthyinae (Buff"aloes), the 

 former group feeding much more freely on mollusks than the latter, and 

 less generally on entomostraca. Of the eight Myxostomas examined, the 

 principal food of each was small, thin-shelled Unionidae (Anodonta), 

 while no entomostraca at all were observed in them, and annulate worms 

 (Naididae) were found in but two specimens. On the other hand, mollusks 

 were found in only four out of fourteen carp and buflfaloes (gasteropods 2, 

 bivalves 2), and in these insignificant in quantity, while large numbers of 

 entomostraca were noticed in twelve of the specimens. The intestines of 

 many of the buff'aloes were filled with a yellowish, shreddy, corpuscular 

 fluid which I could only interpret as altered intestinal mucus and broken 

 down membrane. The fishermen at Peoria report, however, that these fishes 

 frequent the mouths of the gutters from the still-houses of which the river 

 front is redolent, apparently feeding upon the distillery slops. 



43. Red Horse. Myxostoma macrolepidotum, Le S. (3.) Chiefly 

 mollusks, (Unionidae, Physa, Planorbis.) A number of ringed worms (Nai- 

 didae), fragments of Chara and endogenous vegetation, and much mud. 



